Bug 356

Summary:	An error that does not affect normal operation
Product:	Group 8 (2019)	Reporter:	SYR <yuransun2-c>
Component:	Main	Assignee:	yanglou3-c
Status:	CONFIRMED ---
Severity:	trivial	CC:	jiaqchen5-c, leqizheng2-c, xinlinli7-c, yujiaxu4-c, yuransun2-c
Priority:	---
Version:	Version1.0
Hardware:	PC
OS:	Windows

Description SYR 2019-12-05 15:51:17 HKT

Steps to Reproduce:
1. Run the program, and there is some probability to get such an error, but there's no impact on the normal operation.
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: No such child: 68
	at java.desktop/java.awt.Container.getComponent(Container.java:350)
	at java.desktop/javax.swing.JComponent.rectangleIsObscured(JComponent.java:4426)
	at java.desktop/javax.swing.JComponent.paint(JComponent.java:1072)
	at java.desktop/javax.swing.JComponent.paintToOffscreen(JComponent.java:5255)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBufferedFPScales(RepaintManager.java:1707)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1616)
	at java.desktop/javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1556)
	at java.desktop/javax.swing.RepaintManager.paint(RepaintManager.java:1323)
	at java.desktop/javax.swing.JComponent._paintImmediately(JComponent.java:5203)
	at java.desktop/javax.swing.JComponent.paintImmediately(JComponent.java:5013)
	at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:865)
	at java.desktop/javax.swing.RepaintManager$4.run(RepaintManager.java:848)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:848)
	at java.desktop/javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:823)
	at java.desktop/javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:772)
	at java.desktop/javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1884)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)